I would say your doc didn't give you a clear answer, because there is no clear answer. There are lots of women who have 4,5 even 6.. but there are several factors, how long in between sections, how did your uterus wall behave,ie was it thin around your scar?
I hear lots of women's docs say 3... but if your uterus has been strong and not thinned too much then your chances are better.
I am currently scheduled for section 3, although I've had uterus issues, I had a baby attach to my scar 2 years ago, I miscarried and my uterus almost ruptured... so they say it's like I've already had 4 or 5 sections. My uterus has behaved but they are sectioning me early at 38 weeks, and I have had a lot of anxiety towards the end about possibly rupturing and the risk associated with leaving my 2 DS's that I already have with out a mom...
I know when I was looking into the strength of my uterus, I actually went and got copies of my hospital records from my 2 previous sections, to see if there had been any notes in my file about my uterus being "thin" .. .there wasn't, which helped in my decision to have 1 more.
Good luck in your decision! I would suggest doing lots of research and ask your doc lots of questions.
Kim